This invention relates generally to electric cable and, more particularly, to a tool for removing the outer protective jacket from electric cable.
Electric cables buried by local power companies transmit energy to homes in subdivisions. Such cables typically include central coaxial conductors surrounded by a layer of insulating material. The insulating material is surrounded by a sheath of conducting material, and several neutral wires are wrapped helically around the outside of the sheath. Within the last few years, such cable has been provided with an outer protective jacket to shield the cable, especially the copper neutral wires, from soil-induced corrosion. As a result, a need has arisen for a tool capable of readily removing a portion of the jacket so that such cable can be spliced together and/or connected to transformers or other pieces of power transmitting equipment. While several such tools have been developed, none have performed satisfactorily. For example, one such tool has an internal bore coaxial with the outer surface of the tool. Different size tools must be used for each size cable (e.g., #2, 40 and 750 size cable). Because the jacket is formed of tough material, such tools have 14-16 inch (360-410 mm) handles extending radially outwardly from the tool so that the tool can be turned on the cable.
To cut the protective jacket, one end of the coaxial cable is inserted in the internal bore of the tool. The tool is then turned on the cable while a sharp blade projecting radially inwardly from an inner wall of the tool cuts the outer jacket helically down the cable. The blade frequently "hangs up" on out-of-round portions of the cable, becoming jammed on the cable. At this point, the jacket must be cut by a knife to free the tool, and then the whole process must be repeated until sufficient jacket has been stripped away for splicing or connecting the cable.
The cable is often located in tight quarters where it is difficult to manipulate tools during installation and repair. For example, there is typically only a 7-8 inch (180-200 mm) space within a transformer where several electrical cables must be spliced and connected to the transformer. As a result, the handles of the aforementioned cylindrical tool are too long for practical use. If the handles are made shorter, however, the tool cannot be turned to cut the jacket. Another problem is the damage to the inner layers and wiring of the cable caused by the tool's blade while stripping away the outer jacket. This problem becomes particularly acute when the cable is substantially out-of-round.
Another tool for removing the outer protective jacket comprises two opposed V-shaped blades interconnected by a collar or framework and 7-8 inch (180-200 mm) handles. One of the blades is fixed at one side of the framework, and the other blade can be adjusted inwardly and outwardly with respect to the fixed blade according to the size cable. To cut the outer jacket, the cable is inserted between the two V-shaped blades, and the adjustable blade is moved inwardly until it is pressed about 1/16 inches (1-2 mm) into the outer jacket. The tool is then turned to cut away the outer jacket. While this tool is adjustable for different size cables, it has the other shortcomings of the cylindrical tool discussed above.